TH42PX70 First Impressions

By Vincent Teoh21 March 2007, 2:33 pm BST

Ok, stayed up all night after setting up the Panasonic TH42PX70 plasma to rack up the hours stabilising the phosphors. Although uncalibrated, we watched a fair bit of material, so here are our first impressions:

Let’s get the bad out of the way first: our Panasonic TH42PX70 – in its uncalibrated form – still suffers from posterization (aka “false contouring”) and magenta noise (aka “purple snakes”) which plague its predecessor TH42PX60. By using a greyscale ramp test pattern, these problems are most prominent around 30% to 40% stimulus where fine lines of magenta taint the banded greys.

It’s important to stress that the magenta noise is NOT a “switch the tele on… WTF is THAT?” kind of issue: you have to know what you’re looking for – magenta/purple dithering affecting scenes with subtle gradient (most obvious with grey or green) when the colour magenta is not supposed to be present. Panasonic themselves have acknowledged the problem on older sets in an internal bulletin here.

Fortunately in real life, we could only reliably catch the error on our set when sitting very close to the TH42PX70 (say 2 feet away). Watching the notorious underwater scene in Harry Potter & The Goblet Of Fire HD DVD from 8 feet away was a by and large pleasant experience with no purple snakes seen. My point is, the magenta noise in TH42PX70 may not be as bad as that in TH42PX60: it’s still there, but most people will never notice it most of the time.

With that out of my chest, let’s move on to better things. We chose the “Cinema Mode” and “Warm” colour temp from the outset, and were simply blown away by the strikingly harmonious colours. Curious, we measured its greyscale, gamma and contrast ratio, and wow:

Correlated colour temperature near 6500K

Gamma = smooth 2.2 curve

A near-6500K CCT, a smooth 2.2 gamma curve, and a measured contrast ratio (not finalised) of above 1000:1 to boot… and that’s without calibration. And the blacks… I can rave on and on about it, but let’s just cut it short and say that it’s up to Panasonic’s usual excellent standards. I doubt that we can improve on these much more, but will obviously still run some torture test and calibrate our Panasonic TH42PX70 to squeeze out every inch of improvement after the running-in period of 200 hours.

Oops, I’ve rambled on for too long and really should stop now… don’t want to steal Colin’s thunder – he’s working furiously on the initial pages of the full review even as I type…